There's a few instructions that GAS infers operands but Clang doesn't;
from what I can tell the Arm ARM doesn't say these are optional.
F5.1.257 TBB, TBH T1 Halfword variant
F5.1.238 STREXD T1 variant
F5.1.84 LDREXD T1 variant
Link: https://github.com/ClangBuiltLinux/linux/issues/1309
Signed-off-by: Nick Desaulniers <[email protected]>
---
See:
https://lore.kernel.org/linux-arm-kernel/CAMj1kXE5uw4+zV3JVpfA2drOD5TZVMs5a_E5wrrnzjEYc=E_fA@mail.gmail.com/
for what I'd consider V1. The previous issues with .w suffixes have been
fixed or have fixes pending in LLVM:
* BL+DBG: https://reviews.llvm.org/D97236
* ORN/ORNS: https://reviews.llvm.org/D99538
* RSB/RSBS: https://reviews.llvm.org/D99542
I'd have expected the Arm ARM to use curly braces to denote optional
operands (see also "F5.1.167 RSB, RSBS (register)" for an example).
arch/arm/probes/kprobes/test-thumb.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/arch/arm/probes/kprobes/test-thumb.c b/arch/arm/probes/kprobes/test-thumb.c
index 456c181a7bfe..4e11f0b760f8 100644
--- a/arch/arm/probes/kprobes/test-thumb.c
+++ b/arch/arm/probes/kprobes/test-thumb.c
@@ -441,21 +441,21 @@ void kprobe_thumb32_test_cases(void)
"3: mvn r0, r0 \n\t"
"2: nop \n\t")
- TEST_RX("tbh [pc, r",7, (9f-(1f+4))>>1,"]",
+ TEST_RX("tbh [pc, r",7, (9f-(1f+4))>>1,", lsl #1]",
"9: \n\t"
".short (2f-1b-4)>>1 \n\t"
".short (3f-1b-4)>>1 \n\t"
"3: mvn r0, r0 \n\t"
"2: nop \n\t")
- TEST_RX("tbh [pc, r",12, ((9f-(1f+4))>>1)+1,"]",
+ TEST_RX("tbh [pc, r",12, ((9f-(1f+4))>>1)+1,", lsl #1]",
"9: \n\t"
".short (2f-1b-4)>>1 \n\t"
".short (3f-1b-4)>>1 \n\t"
"3: mvn r0, r0 \n\t"
"2: nop \n\t")
- TEST_RRX("tbh [r",1,9f, ", r",14,1,"]",
+ TEST_RRX("tbh [r",1,9f, ", r",14,1,", lsl #1]",
"9: \n\t"
".short (2f-1b-4)>>1 \n\t"
".short (3f-1b-4)>>1 \n\t"
@@ -468,10 +468,10 @@ void kprobe_thumb32_test_cases(void)
TEST_UNSUPPORTED("strexb r0, r1, [r2]")
TEST_UNSUPPORTED("strexh r0, r1, [r2]")
- TEST_UNSUPPORTED("strexd r0, r1, [r2]")
+ TEST_UNSUPPORTED("strexd r0, r1, r2, [r2]")
TEST_UNSUPPORTED("ldrexb r0, [r1]")
TEST_UNSUPPORTED("ldrexh r0, [r1]")
- TEST_UNSUPPORTED("ldrexd r0, [r1]")
+ TEST_UNSUPPORTED("ldrexd r0, r1, [r1]")
TEST_GROUP("Data-processing (shifted register) and (modified immediate)")
--
2.31.0.291.g576ba9dcdaf-goog
Thanks for the patch. It looks good to me, and I double checked ARM
architecture reference manual for V7 and can confirm the missing
operand in these instructions is not specified as optional.
Reviewed-by: Jian Cai <[email protected]>
On Mon, Mar 29, 2021 at 3:12 PM Nick Desaulniers
<[email protected]> wrote:
>
> There's a few instructions that GAS infers operands but Clang doesn't;
> from what I can tell the Arm ARM doesn't say these are optional.
>
> F5.1.257 TBB, TBH T1 Halfword variant
> F5.1.238 STREXD T1 variant
> F5.1.84 LDREXD T1 variant
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/1309
> Signed-off-by: Nick Desaulniers <[email protected]>
> ---
> See:
> https://lore.kernel.org/linux-arm-kernel/CAMj1kXE5uw4+zV3JVpfA2drOD5TZVMs5a_E5wrrnzjEYc=E_fA@mail.gmail.com/
> for what I'd consider V1. The previous issues with .w suffixes have been
> fixed or have fixes pending in LLVM:
> * BL+DBG: https://reviews.llvm.org/D97236
> * ORN/ORNS: https://reviews.llvm.org/D99538
> * RSB/RSBS: https://reviews.llvm.org/D99542
> I'd have expected the Arm ARM to use curly braces to denote optional
> operands (see also "F5.1.167 RSB, RSBS (register)" for an example).
>
> arch/arm/probes/kprobes/test-thumb.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/arch/arm/probes/kprobes/test-thumb.c b/arch/arm/probes/kprobes/test-thumb.c
> index 456c181a7bfe..4e11f0b760f8 100644
> --- a/arch/arm/probes/kprobes/test-thumb.c
> +++ b/arch/arm/probes/kprobes/test-thumb.c
> @@ -441,21 +441,21 @@ void kprobe_thumb32_test_cases(void)
> "3: mvn r0, r0 \n\t"
> "2: nop \n\t")
>
> - TEST_RX("tbh [pc, r",7, (9f-(1f+4))>>1,"]",
> + TEST_RX("tbh [pc, r",7, (9f-(1f+4))>>1,", lsl #1]",
> "9: \n\t"
> ".short (2f-1b-4)>>1 \n\t"
> ".short (3f-1b-4)>>1 \n\t"
> "3: mvn r0, r0 \n\t"
> "2: nop \n\t")
>
> - TEST_RX("tbh [pc, r",12, ((9f-(1f+4))>>1)+1,"]",
> + TEST_RX("tbh [pc, r",12, ((9f-(1f+4))>>1)+1,", lsl #1]",
> "9: \n\t"
> ".short (2f-1b-4)>>1 \n\t"
> ".short (3f-1b-4)>>1 \n\t"
> "3: mvn r0, r0 \n\t"
> "2: nop \n\t")
>
> - TEST_RRX("tbh [r",1,9f, ", r",14,1,"]",
> + TEST_RRX("tbh [r",1,9f, ", r",14,1,", lsl #1]",
> "9: \n\t"
> ".short (2f-1b-4)>>1 \n\t"
> ".short (3f-1b-4)>>1 \n\t"
> @@ -468,10 +468,10 @@ void kprobe_thumb32_test_cases(void)
>
> TEST_UNSUPPORTED("strexb r0, r1, [r2]")
> TEST_UNSUPPORTED("strexh r0, r1, [r2]")
> - TEST_UNSUPPORTED("strexd r0, r1, [r2]")
> + TEST_UNSUPPORTED("strexd r0, r1, r2, [r2]")
> TEST_UNSUPPORTED("ldrexb r0, [r1]")
> TEST_UNSUPPORTED("ldrexh r0, [r1]")
> - TEST_UNSUPPORTED("ldrexd r0, [r1]")
> + TEST_UNSUPPORTED("ldrexd r0, r1, [r1]")
>
> TEST_GROUP("Data-processing (shifted register) and (modified immediate)")
>
> --
> 2.31.0.291.g576ba9dcdaf-goog
>